Method and device for recording real-time information

ABSTRACT

A method and device for recording real time information on a record carrier, e.g. video on an optical disc. The information is arranged according to a recording format, e.g. DVD video, for being playable in standardized players. The information is subdivided into units and playback parameters for reproducing sequences of the units are included in the units. The format prescribes forward pointers to units that are located at a large distance from the unit which includes the forward pointers. However for home recording it is required that a recording is made in one pass, i.e. the video is to be recorded directly at its final location without a large buffer. So the device has a small buffer ( 30 ), and a processing unit ( 20,28 ) for determining pointers to nearby units based on the buffer contents, while values for pointers pointing far forward are set arbitrarily, based on nearby units and/or default values indicating that the unit intended to be pointed to does not exist. Standard playback devices can still play the recorded material in trickplay modes with only minor deviations in the fast forward scanning speed.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of prior application Ser. No. 10/270,399 filedOct. 11, 2002, now U.S. Pat. No. 6,748,159.

The invention relates to a method of recording real time information andplayback parameters related thereto on a record carrier arrangedaccording to a recording format, in which method the real timeinformation is subdivided into units and the playback parameters aregenerated and included in the units, which playback parameters comprisepointers to units located at a forward and/or backward distance relativeto the unit in which the pointers are included.

The invention further relates to a device for recording real timeinformation and playback parameters related thereto on a record carrierarranged according to a recording format, the recorder comprisingprocessing means for subdividing the real time information into unitsand for generating the playback parameters to be included in the units,which playback parameters comprise pointers to units located at aforward and/or backward distance relative to the unit in which thepointers are to be included.

A method of recording real-time information on a record carrier is knownfrom EP 814475. Real-time information is information having a real-timenature to be reproduced at a prescribed rate, usually audio or videoinformation, or a combination of audio and video. In the known methodvideo information is encoded digitally and subdivided into units, whichare short, but independently reproducible segments of the real-timeinformation, while corresponding audio information may be included inthe units. Control information for accessing and reproducing thereal-time material is generated for enabling several playback functions.A user playable program usually called a title, for example a movie, isconstituted by a sequence of units and corresponding controlinformation. Part of the control information, so called playbackparameters, are included in the units to enable playback control byusing information stored with the related real-time information itself,which reduces the need for memory in the player for storing controlinformation read from separate tables, such as address lists of units.In particular, the playback parameters comprise pointers to unitslocated at a distance in forward or backward direction, usually at fixedintervals in playback time. As the units are stored on the recordcarrier consecutively, said distance corresponds to a distance along thetrack between the unit comprising said pointers and such forward andbackward units. In the event of a variable bitrate real-time signal,e.g. video after compression by MPEG2, no fixed relation exists betweenthe distance in time and along the track. Also other data, e.g. in theevent of multiplexed audio, video and text, may cause a non predictabledistance along the track. So said pointers are used in jumps to otherunits relative to the unit just read. The user may play the movie atstandard speed reading the units consecutively, but he may also scan thematerial in trick play modes, e.g. fast forward or reverse slow motion,using the playback parameters in the units pointing in forward and/orbackward direction. The way the control information and the real-timeinformation are provided on a record carrier is standardized to enableplayers of different brands to reproduce the material. An example ofsuch a standard is the DVD-video standard, of which the relevantaspects, such as the playback parameters, are described in said EP814475. In the known recording method the playback parameters aregenerated separately after the video material has been gathered andstored temporarily in a memory, e.g. on a video tape. The real-timeinformation and control information are finally transferred to therecord carrier by well known mastering and reproducing steps, e.g.pressing optical discs from a metal master disc. A problem of the knownrecording method is, that a temporary storage of the real-timeinformation is required before the control information and playbackparameters can be generated. On the final product, the record carrier,the playback parameters are to be positioned according to the formatrules, which prescribe that the playback parameters are included in theunits with the real-time information. However the playback parameterscan be generated only after the real-time material is known in forwarddirection for a period sufficient to determine the prescribed forwardpointers, and therefore a large amount of real time information needs tobe stored temporarily. Hence the known method of recording iscomplicated and expensive, in particular in view of home recording.

It is an object of the invention to provide a recording method anddevice in which real-time information can be recorded according to anexisting format and which is less complex.

For this purpose, the method as described in the opening paragraph ischaracterized in that the method comprises the steps of

-   buffering the real time information for a period before recording,-   determining a value for at least one of said pointers based on the    buffered real time information,-   calculating a value for at least a further one of said pointers    intended to point to a unit located at a forward distance larger    than said period, based on the buffered real time information and/or    a predefined value, and-   recording the buffered real time information together with said    determined and calculated values.    During recording some pointer values are determined as prescribed in    the recording format based on buffered real-time information in a    relatively small buffer. However, further values for pointers    intended to point at units further away in forward direction than    the period available in the buffer are calculated different from the    values prescribed in the recording format. The calculated values are    based on units which are present in the buffer, i.e. which are not    as far away as intended, or on predefined values, e.g. indicating    that a jump-address is not available. This has the effect, that a    real-time recording can be made in one pass, i.e. the real-time    information is recorded on a record carrier of a writable type    directly at its final location without temporary storage, while the    playback parameters are generated during recording.

The invention is also based on the following recognition. Formatsintended for mastered and mass produced record carriers of a read-onlytype may prescribe a non-causal order in which playback parametersprecede the recorded audio/video, because this is the order playbackdevices require the information for reproduction. Non-causalityinherently arises during recording, because one cannot calculate pointervalues for video material not yet available, in particular if the videois compressed to a variable length digital code such as MPEG2. For aprofessional recording studio this presents no problem, as theaudio/video material is always stored in its entirety in a temporarystorage device, e.g. on a master video tape, before the final authoringprocess is performed, in which the playback parameters are determined.In a home recorder one-pass recording is required, and therefore theDVD-video format seems unsuitable. However the inventors have seen, thatplayback devices respond in a predefined way to some calculated orpredefined values for playback parameters which deviate from theprescribed values, for example by using a different jumping mechanism,e.g. in DVD players for fast forward a jump to a next cell is performedwhen the playback parameters indicate that no forward unit is availablein the cell. So the prescribed playback parameters included in the unitscan be acceptably approached by setting the pointers pointing farforward to some calculated or predefined value. In that event thescanning mode may be somewhat faster then intended, because in saidscanning mode jumps are made from cell to cell based on a cell addresstable present elsewhere in the DVD format, instead of the shorter jumpsoriginally intended. The scanning mode may alternatively be somewhatslower, if the pointer values are calculated to point at existing unitsless far away than intended.

According to the invention the device as described in the openingparagraph is characterized as claimed in claim 5. Preferred embodimentsof the method and device according to the invention are given in thedependent claims.

These and other aspects of the invention will be apparent from andelucidated further with reference to the embodiments described by way ofexample in the following description and with reference to theaccompanying drawings, in which

FIG. 1 shows a record carrier,

FIG. 2 shows a recording device,

FIG. 3 shows volume space on an optical disk,

FIG. 4 shows the logical structures of the video manager and the videotitle sets in more detail,

FIG. 5 shows a relationship between video object set and cells and thecontents of the cells hierarchically,

FIG. 6 shows a diagram of controlling the sequence of playback of thecells by a program chain,

FIG. 7 shows a relationship between a video object unit and video packsin the unit,

FIG. 8 shows video title set information in a video title set,

FIG. 9 shows the contents of a video title set program chain informationtable,

FIG. 10 shows the structure, of program chain information,

FIG. 11 shows cell playback information and the contents thereof,

FIG. 12 shows the contents of a cell position information table,

FIG. 13 shows the formats of a pack and a packet recorded on an opticaldisk,

FIG. 14 shows an NV_PCK pack,

FIG. 15 shows information described in the data search generalinformation,

FIG. 16 shows information described in the seamless playbackinformation,

FIG. 17 shows the contents of the seamless angle information,

FIG. 18 shows the VOBU search information,

FIG. 19 shows the structure of audio synchronization information, and

FIG. 20 shows the recording method according to the invention.

Corresponding elements in different Figures have identical referencenumerals.

FIG. 1 a shows a disc-shaped record carrier 11 having a track 9 and acentral hole 10. The track 9 is arranged in accordance with a spiralpattern of turns constituting substantially parallel tracks on aninformation layer. The record carrier may be optically readable, calledan optical disc, and has an information layer of a recordable type.Examples of a recordable disc are the CD-R and CD-RW, and writableversions of DVD, such as DVD-RAM and DVD+RW. The track 9 on therecordable type of record carrier is indicated by a pre-embossed trackstructure provided during manufacture of the blank record carrier. Thetrack structure is constituted, for example, by a pregroove 14 whichenables a read/write head to follow the track during scanning. Theinformation is represented on the information layer by opticallydetectable marks recorded along the track, e.g. pits and lands.

FIG. 1 b is a cross-section taken along the line b-b of the recordcarrier 11 of the recordable type, in which a transparent substrate 15is provided with a recording layer 16 and a protective layer 17. Thepregroove 14 may be implemented as an indentation or an elevation, or asa material property deviating from its surroundings.

The record carrier 11 is intended for carrying real-time informationaccording to a standardized format, to be playable on standardizedplayback devices. The recording format includes the way information isrecorded, encoded and logically mapped. The logical mapping may comprisea subdivision of the available area in a lead-in 18, a recording areafor user data and a lead-out 19. Further the mapping may comprise filemanagement information for retrieving the user information, such as aTable Of Contents or a file system, e.g. ISO 9660 for CD-ROM or UDF forDVD-ROM. Such file management information is mapped on a predefinedlocation on the record carrier, usually in or directly after the lead-inarea. However this document further relates to aspects of the formatrelating to the way the real-time information is recorded, i.e. formatof the video and/or audio information and its corresponding controlinformation. The record carrier 11 is provided with a starting point 13for creating a free area 12 for accommodating control informationrelated to recorded real-time information. The real-time recordingprocess is described below with reference to FIG. 20.

FIG. 2 shows a recording device for writing information on a recordcarrier 11 of a type which is (re)writable. The device is provided withdrive means 21 for rotating the record carrier 1, and a head 22 forscanning the track on the record carrier. The apparatus is provided withpositioning means 25 for coarsely positioning the head 22 in the radialdirection on the track. The head comprises an optical system of a knowntype for generating a radiation beam 24 guided through optical elementsfocused to a radiation spot 23 on a track of the information layer ofthe record carrier. The radiation beam 24 is generated by a radiationsource, e.g. a laser diode. The head further comprises a focusingactuator for moving the focus of the radiation beam 24 along the opticalaxis of said beam and a tracking actuator for fine positioning of thespot 23 in a radial direction on the center of the track. The trackingactuator may comprise coils for radially moving an optical element ormay be arranged for changing the angle of a reflecting element. Forwriting information the radiation is controlled to create opticallydetectable marks in the recording layer. For reading the radiationreflected by the information layer is detected by a detector of a usualtype, e.g. a four-quadrant diode, in the head 22 for generating a readsignal and further detector signals including a tracking error and afocusing error signal coupled to said tracking and focusing actuators.The read signal is processed by a reading means of a usual type (notshown) to retrieve the information. The device comprises recording meansfor processing the real-time information to generate a write signal todrive the head 22. The recording means comprise an input unit 27, aformatting unit 28, a modulation unit 29 and a control unit 20 forreceiving commands from a user or from a host computer. The formattingunit is coupled to a buffer unit 30 for temporarily storing the incomingreal-time data. The control unit 20 is connected via control lines 26,e.g. a system bus, to said recording means, the buffer means 30, thedrive means 21, and the positioning means 25. The control unit 20comprises control circuitry, for example a microprocessor, a programmemory and control gates, for performing the procedures and functionsaccording to the invention as described below with reference to FIG. 20.The control unit 20 may also be implemented as a state machine in logiccircuits. The control unit 20 and the formatting means 28 constituteprocessing means for subdividing the real time information into unitsand for generating playback parameters to be included in the units,which playback parameters comprise pointers to units located at aforward and/or backward distance relative to the unit in which thepointers are to be included. The recording method as performed by theprocessing means is described below in detail with reference to FIG. 20.During the writing operation, marks representing the information areformed on the record carrier. The marks may be in any optically readableform, e.g. in the form of areas with a reflection coefficient differentfrom their surroundings, obtained when recording in materials such asdye, alloy or phase change material, or in the form of areas with adirection of magnetization different from their surroundings, obtainedwhen recording in magneto-optical material. Writing and reading ofinformation for recording on optical disks and usable formatting, errorcorrecting and channel coding rules are well-known in the art, e.g. fromthe CD system. The marks can be formed by means of a spot 23 generatedon the recording layer via a beam 24 of electromagnetic radiation,usually from a laser diode. The recording means further include an inputunit 27, a formatting unit 28, and a modulation unit 29. Userinformation is presented on the input unit 27, which may comprise ofcompression means for analog audio and/or video, or for digitaluncompressed audio/video. Suitable compression means are described foraudio in WO 98/16014-A1 (PHN 16452) and for video in the MPEG2 standard.From the input unit 27 the data is passed to the formatting unit 28 foradding control data and formatting the data according to the recordingformat. The data stream to be recorded is passed to the modulation unit29, which drives the head 22, and which comprises for example an errorcoder and a channel coder. The data presented to the input of themodulation unit 29 is written to sectors on the record carrier under thecontrol of control unit 20. Usually the recording apparatus will also bearranged for reading having the reading and decoding means of a playbackapparatus and a combined write/read head.

First a recording format is described. The format substantiallycorresponds to the DVD-Video standard.

FIG. 3 shows volume space on the optical disk 11. As shown in FIG. 3,the volume space consists of a volume and file configuration zone, aDVD-video zone, and other zones. In the volume and file configurationzone is described a UDF (Universal Disk Format Specification Revision1.02) configuration, the data of which can be read by any computer thatmeets a predetermined standard. The DVD-video zone has a video manager(VMG) and a video title set (VTS). The video manager (VMG) and the videotitle set (VTS) each consist of multiple files. The video manager (VMG)is information for controlling the video title set (VTS).

In FIG. 4 shows the structures of the video manager (VMG) and the videotitle set (VTS) in more detail. The video manager (VMG) has videomanager information (VMGI) as control data and a video object set(VMGM_VOBS) as data for menu display. Also, backup video managerinformation (VMGI_BUP) that is identical in content to the VMGI isincluded. The video title set (VTS) contains video title set information(VTSI) as control data, optionally a video object set (VTSM_VOBS) asdata for menu display, and a video object set (VTSTT_VOBS) for thetitle(s) of a video title set that is a video object set for videodisplay. Also, backup video title set information (VTSI_BUP) that isidentical in content to the VTSI is included. The video object set(VTSTT_VOBS) for video display is made up by multiple cells grouped inVOBs. Each cell in a VOB is assigned a cell identification number.

FIG. 5 shows a relationship between the video object set (VOBS) and thecells and the contents of the cells hierarchically. When DVD playbackprocessing is performed, video breaks (scene changes, angle changes,story changes, etc.) and special playback are handled in units of cells(Cell), or in interleaved units (ILVU), or in units of video objectunits (VOBU) that are in a layer below the cells. First, the videoobject set (VOBS) comprises multiple video objects (VOB_IDN1 toVOB_IDNi). Moreover, one video object comprises multiple cells (C_IDN1to C_IDNj). Furthermore, one cell (cell) comprises multiple video objectunits (VOBU) or interleaved units that are described later. One videoobject unit (VOBU) comprises one navigation pack (NV_PCK), multipleaudio packs (A_PCK), multiple video packs (V_PCK), and multiplesubpicture packs (SP_PCK). The navigation pack (NV_PCK) is mainly usedas control data for control of reproduced display of data in the videoobject unit to which it belongs and control data for search for data inthe video object unit. The video pack (V_PCK) is main video information,which is compressed in accordance with the MPEG2 standard or the like.The subpicture pack (SP_PCK) is sub video information having contentsthat are auxiliary to main video, such as subtitles. The audio pack(A_PCK) is sound information.

FIG. 6 shows a diagram of controlling the sequence of playback of thecells (Cells) by a program chain (PGC). As the program chain (PGC),various program chains (PGC#1, PGC#2, PGC#3, . . . ) are prepared so asto allow the order of playback of data cells to be set variously.Therefore, the order of playback of cells will be set by making a choiceamong the program chains. An example in which program #1 to program #ndescribed by program chain information (PGCI) are executed is shown. Theprogram shown has the contents to specify a cell specified by(VOB_IDN#s, C_IDN#1) and subsequent cells within the video object set(VOBS) in turn. The program chain, recorded on the managementinformation recording area of the optical disk, is information that isread prior to the reading of the video title set of the optical disk andthen stored in the memory in the system controller. The managementinformation is placed at the beginning of the video manager and eachvideo title set.

FIG. 7 shows a relationship between a video object unit (VOBU) and videopacks in it. Video data in VOBU comprises one or more GOPs (GOP=Group OfPictures). Encoded video data conforms to MPEG2 (ISO/IEC13818-2) by wayof example. The GOP in VOBU comprises an I-picture P- and B-pictures andthe continuation of this data is divided into video packs. Next, adescription is given of a data unit when multi-angle information isrecorded and reproduced. When multiple scenes that differ in point ofview for a subject are recorded on an optical disk, an interleaved-blockportion is built on recording tracks to perform seamless playback. Inthe interleaved block portion, multiple video objects (VOB) that differin angle are each divided into multiple interleaved units. Theinterleaved units are recorded in such an arrangement as allows seamlessplayback. Multiple stories may be interleaved on a kind of time divisionbasis. In the description, all of the divided blocks were termed cells.Next, a description will be given of the interleaved units andmanagement information used for playing back the interleaved units.

FIG. 8 shows video title set information (VTSI) in video title set(VTS). A video title set program chain information table (VTS_PGCIT) isdescribed in the video title set information (VTSI). Thus, when a videoobject set (VOBS) in one video title set (VTS) is played back, a programchain is utilized which is specified by the producer or selected by theuser from multiple program chains presented in the video title setprogram chain information table (VTS_PGCIT). In the VTSI, the followingdata are further described. VTSI_MAT is a video title set informationmanagement table, in which what kinds of information are present in thisvideo title set and the starting and ending addresses of each item ofinformation are described. VTS_PTT_SRPT is a video title setpart-of-title search pointer table, in which entry points of titles andthe like are described. VTSM_PGCI_UT is a video title set menu programchain information unit table, in which a menu of video title sets isdescribed in various languages. Thus, the menu allows the user todetermine what kind of video title set is described and what style oforder playback can be performed in. VTS_TMAPT is a video title set timemap table, in which information on the recorded position of each VOBU isdescribed which is managed within each program chain and indicated atregular intervals of seconds. VTSM_C_ADT is a video tile set menu celladdress table, in which the starting and ending address of each cellcomprising the video title set menu and the like are described.VTSM_VOBU_ADMAP is a video title set menu video object unit address map,in which the starting addresses of menu video object units aredescribed. VTS_C_ADT is a video title set cell address table, in whichcell address information is described. When a program chain is selectedin the playback apparatus, the order of playing back cells is set bythat chain. In playback, NV_PCK included in the video object unit isreferred to. NV_PCK has information for controlling display contents anddisplay timing and information for data search Thus, the retrieval anddecoding of V_PCK are performed on the basis of information in theNV_PCK table. In addition, another pack is retrieved and decoded, inwhich case A_PCK and SP_PCK in a language specified by the producer oruser are retrieved.

FIG. 9 shows the contents of the video title set program chaininformation table (VTS_PGCIT). In this table are described video titleset PGCI table information (VTS_PGCITI), search pointers (VTS_PGCI_SRP#1to #n) for video title set program chain information, and specificprogram chain information (VTS_PGCI). In (VTS_PGCITI) are described thenumber of search pointers and the ending address of this table. In(VTS_PGCI_SRP#1 to #n) are described, as the category of the video tileset program chain, the number of titles in a video title set thatbecomes a target, whether the program chain ends with one block orcontinues into a chain in another block, etc. In addition, the startingaddress of the video title set program chain is described in terms ofthe relative address to the starting position of this table.

FIG. 10 describes the contents of program chain information (PGCI). ThePGCI contains program chain general information (PGCI_GI), a programchain command table (PGC_CMDT), a program chain program map (PGC_PGMAP),cell playback information (C_PBI), and cell position information table(C_POSIT). In the PGCI_GI are described the number of programs and thenumber of cells for this program chain (this information is called PGCcontents (PGC_CNT)). In addition, all the playback times that theprogram chain intends are shown (this information is called PGC playbacktime (PGC_PB_TM)). Moreover, a code of whether a program played back bythis program chain allows user operation, for example, whether theswitching of angles is possible, is described (this information iscalled PGC user operation control (PGC_UPR_CTL)). Furthermore, codes ofwhether audio streams can be switched and what type of audio stream(e.g. linear PCM, AC-3, MPEG or the like) can be switched into are alsodescribed (this information is called PFC audio stream control table(PGC_AST_CTLI). In addition, codes of whether subvideos can be switchedand what type of subvideo (e.g., a different aspect ratio) can beswitched into are described (this information is called PGC subvideostream control table (PGC_SPST_CTLT). Moreover, in this PGCI_GI, thenext program chain number and the previous program chain number are alsodescribed. Furthermore, whether the program intended by this programchain is intended for continuous playback, random playback, or shuffleplayback is also described (this information called PGC navigationcontrol (PGC_NV_CTL). In addition, color specification is performed toindicate what colors subvideo is to be displayed in (this information iscalled PGC subvideo palette (PGC_SP_PLI)). Also, the starting address ofthe program chain command table (PGC_CMDT_SA), the starting address ofthe program chain program map (PGC_PGMAP_SA), the starting address ofthe cell playback information table (C_PBIT_SA) and the starting addressof cell position information (C_POSI_SA) are described. In the programchain command table are described the pre-commands and post-commands ofthe program chain and cell commands. The pre-commands are ones to beprocessed prior to the execution of the program chain and thepost-commands are ones to be processed after the execution of theprogram chain. The pre-commands and post-commands are used to define thevideo title, the reproduced state of audio, and the reproduced stream onthe basis of commands or parameters decided in advance on the playerside or the disk producer side. The cell commands are ones to beprocessed subsequent to the execution of playback processing of cells.In the starting address of the program chain program map (PGC_PGMAP),the structure of a program for which the program chain is intended isindicated and entry cell numbers of an existing program are described.In the cell playback information table (C_PBIT) is described informationindicating the order of playing back cells for which the program chainis intended.

FIG. 11 shows cell playback information (C_PBIT) and its contents. TheC_CAT is cell attribute information and indicates the mode of a cellblock. The mode of a cell block indicates whether the cell is the firstone or the last one. Also included are information as to whetherseamless playback is to be performed, information as to whether the cellblock is among interleaved blocks, and information about seamless angleswitching. The information about seamless angle switching indicates thatthe angle switching can be made either seamlessly or non-seamlessly.C_PBTM indicates the cell playback time, C_FVOBU_SA the starting addressof the first video object unit (VOBU) of the cell, C_ILVU_EA the endingaddress of the first interleaved unit (ILVU) of the cell, C_FVOBU_SA thestarting address of the last video object unit (VOBU) of the cell, andC_FVOBU_EA the ending address of the last video object unit (VOBU) ofthe cell. The addresses are described in terms of logical block numbersrelative to the first logical block of VOB to which the cell belongs. Byreferring to the cell playback information, a determination can be madeof whether the current playback state reaches the end of a cell. Whenthe next cell is played back the next cell playback information in thecell playback information table is referred to determine the startingaddress of the first VOBU of the next cell (or interleaved unit).

FIG. 12 shows the contents of the cell position information table(C_PSIT). The cell position information includes the ID number of avideo object (C_VOB_IDN) in which the cell is contained and the cell IDnumber (C_IDN) of the cell. As described above, the managementinformation describes cell playback information, in which there is cellattribute information indicating whether interleaved units for multipleangles or the like have been recorded. When a multi-angle video or amulti-story video is recorded, the playback apparatus needs to switchfrom the angle being played back to the other or switch from the storybeing played back to the other according to user's operation. In thiscase, the playback apparatus responds to the user's operation on thebasis of the following information. First, the structure of a pack willbe described.

FIG. 13 shows the formats of one pack and one packet. One pack comprisesa pack header and a packet. In the packet header are described a packstart code, a system clock reference (SCR), etc. The pack start code isone indicating the beginning of the pack, and the system clock reference(SCR) is information indicating to the entire playback apparatus thereference time in the playback elapsed time. One pack is defined andrecorded as one logical block on an optical disk. One packet comprises apacket header and video data or audio data or subpicture data, ornavigation data. Stuffing may be provided in the packet header. Paddingmay be provided in the data division of the packet.

FIG. 14 shows the NV_PCK (see FIG. 5). The NV_PCK includes a picturecontrol information (PCI) packet basically adapted to control displaypictures and a data search information (DSI) packet existing in the samevideo object. In each packet are described a pack header and a substreamID, followed by data. In each pack header is described a stream ID,indicating NV_PCK. The substream ID is used to distinguish between PCIand DSI. In each pack header are described a packet start code, a streamID and the packet length, followed by data. The PCI packet is navigationdata for changing display contents synchronously with the playback ofvideo data in a video object unit (VOBU) to which the NV packet belongs.In the PCI packet are described PCI general information (PCI_GI) that isgeneral information, non-seamless angle information (NSML_ANGLI),highlight information (HLI) and recording information (RECI) that isrecorded information. In the PCI_GI is described PCI generalinformation, which includes: the logical block number (NV_PCK_LBN) thatis the address of the navigation pack, the video object unit category(VOBU_CAT) indicating the attribute of a video object unit (VOBU)managed by the PCI, the user operation control (VOBU_UPO_CTL) that isuser operation inhibit information in the display period of the videoobject unit managed by the PCI the video object unit display startingtime (VOBU_S_PTM), and the video object unit display ending time(VOBU_E_PTM). The first picture specified by the VOBU_S_PTM is anI-picture in the MPEG standards. Further, video object unit sequence endpresentation time

(VOBU_SE_E_PTM) indicating the display time of the last video in thevideo object unit, the cell elapsed time (C_ELTM) indicating the displayelapsed time relative to the first video frame in a cell and so on arealso described. The NSML_ANGL indicates the destination address when anangle change is made. That is, the video object unit includes picturesshot from different angles. The address of a VOBU is described to whicha transition is made for the next playback when the display of picturesshot from a different angle from the current one is specified by theuser. The HLI is information for specifying a specific rectangular areaon the screen and changing the brightness of that area or the color ofsubvideo displayed therein. The information includes highlight generalinformation (HL_GI), a button color information table (BTN_COLIT) usedwhen the user makes a selection among buttons for color selection, andbutton information table (BTNIT) for select buttons. The RECI isinformation about video, audio and subpicture recorded in the videoobject unit, each item of information describing what data to be decodedis like. For example, a country code, a copyright owner code and thedate of recording are included. The DSI packet is navigation data formaking a search for a video object unit. In the DSI packet are describedDSI general information (DSI_GI), seamless playback information(SML_PBI), seamless angle information (SML_AGLI), video object unitsearch information (VOBU_SRI), and sync information (SYNCI).

As shown in FIG. 15, in the DSI_GI is described the followinginformation: a system clock reference indicating the reference time forstarting decoding the NV_PCK (NV_PCK_SCR), the logical address of theNV_PCK (NV_PCK_LBN), the ending address of the video object unit towhich the NV_PCK belongs (VOBU_EA), the ending address of the firstreference picture (I-picture) to be decoded first (VOBU-1STRSEF-EA), theending address of the second reference picture (I or P-picture) to bedecoded first (VOBU-2NDREF_EA), the ending address of the thirdreference picture (I or P-picture) to be decoded first (VOBU_3RDREF_EA),the ID number of the VOB to which the DSI belongs (VOBU_VOB_IDN), the IDnumber of the cell to which the DSI belongs (VOBU_C_IDN), and the cellelapsed time indicating the elapsed time relative to the first videoframe in the cell (C_ELTM).

As shown in FIG. 16, in the SML_PBI is described the followinginformation: video object unit seamless category indicating whether theVOBU to which the DSI belongs is an interleaved unit (ILVU) or apre-unit (PREU) that is the criterion for indicating the connectionbetween video objects, the ending address of the interleaved unit(ILVU_EA), the starting address of the next interleaved unit (ILVU_SA),the size of the next interleaved unit (ILVU_SZ), the video displaystarting time in the video object (VOB) (VOB_V_S_PTM), the video displayending time in the video object (VOB) (VOB_V_E_PTM), the audio stoppingtime in the video object (VOB) (VOB_A_STP_PTM), and the audio gap lengthin the video object (VOB) (VOB_A_GAP_LEN). The pre-unit (PREU) is thelast unit immediately before the interleaved unit. In the video objectunit seamless, category (VOBU_SML_CAT) are further described a flagindicating whether or not the interleaved unit is one at the startingtime and a flag indicating whether the interleaved unit is one at theending time.

FIG. 17 shows the contents of the seamless angle information (SML_GLI).C1 to C9 indicate the number of angles. Even if a maximum of nine anglesexists, the addresses and sizes of their destination interleaved unitscan be indicated. That is, the addresses and sizes (SML_ADL_Cn_DSTA)(n=1 to 9) of interleaved units that are destinations for the respectiveangles are described. When the user performs an operation of changingthe angle while watching video, this operation information is referencedto, thereby allowing the playback apparatus to recognize the playbackposition of the next interleaved unit.

FIG. 18 shows VOBU search information (VOBU_SRI) which is referenced toat the time of special playback, etc. The information describes thestarting addresses of VOBUs (0.5×n) seconds before and after thestarting time of the current video object unit (VOBU). That is, thestarting address of each of +1, +20, +60, +120 and +240 VOBUs as forwardaddresses (FWDIn) and a flag that a video pack is present in the unitare described according to the order of playback with the VOBUcontaining the DSI being referenced to. The starting address isdescribed in terms of the number of logical sectors relative to theleading logical sector in the VOBU.

FIG. 19 shows sync information. In this sync information are describedthe address of an object audio pack to be synchronized and the VOBUstarting address of an object video pack to be synchronized.

The above-described management information is described on an opticaldisk The system controller of the playback system makes a reference tothe program chain information in the video manager to thereby acquirecell playback information. By referring to the cell attributeinformation, whether interleaved unit blocks for multiple angles havebeen recorded is recognized. When the interleaved unit blocks have beenrecorded, seamless playback information and seamless angle informationin the NV_PCK are acquired and stored in the buffer memory in the middleof playback. When angle switching information is entered by the user,the seamless angle information is referenced to, whereby the playback ofinterleaved units for the angle specified by the user is started. Then,reference is made to the seamless cell playback information contained inthe acquired NV_PCK to recognize the interleaved unit to be played backnext. By referencing to the cell playback information, a decision can bemade as to whether it is the end of a cell that is currently playedback. To play back the next cell, reference is made to the next cellplayback information in the cell playback information table to determinethe starting address of the first VOBU of the next cell.

According to the invention the control unit 20 of the recording deviceas shown in FIG. 2 is arranged for recording real-time informationaccording to the following method.

FIG. 20 shows a real-time recording method for recording real-timeinformation according to a recording format. For the below example theDVD-video format as described above, is used. It is to be noted, thatthe DVD format comprises units of data, the above describe VOBUs , whichcomprise the real-time information and playback parameters. A recordingsession starts at a start 200, e.g. by a user command, and is completedat stop 208, e.g. when a programmed recording is completed. In a firststep 201 (START RECORDING), provided a record carrier is inserted in therecording device, the input of real-time information is started. In asecond step 202 (BUFFER PERIOD) the first period of real-timeinformation comprising a number of units is stored in a (relativelysmall) buffer, e.g. VOBUs for a few seconds of video. In a third step203 (CALCULATE POINTERS) pointer values which are required in the firstunit (VOBU) are determined from the stored data in the buffer, and infurther processing loops also the pointers for past VOBUs aredetermined, e.g. by storing addresses in a memory in the control unit20. In particular pointers for units not yet available in the buffer aresubstituted by calculated values, which deviate from the valuesprescribed in the recording format. The calculation is given below. In afourth step 204 (STORE UNIT) the completed real-time information andplayback parameters are recorded on the record carrier. In a test 205 itis determined, if more real-time information is present at the input. Ifso, in a next step 206 (BUFFER NEXT UNIT) the next amount of real-timeinformation is buffered, at the same time removing the already storedfirst unit. The last four steps 203, 204, 205 and 206 are repeated untilthe recording is finished, which is tested by said test 205. Iffinished, the last part of the buffered information and remainingcontrol data is stored in step 207. Said calculation for forwardreferences is described below and is performed by a multiplexer functionwithin the control unit 20 in cooperation with the formatting unit 28,constituting part of said processing means.

It is the task of the multiplexer to parse and multiplex the inputelementary stream (audio, video and sub pictures) into a VOB comprisingVOBUs. The types of packs in the VOBU may be seen as packs containingdynamic navigation data and packs containing presentation data (VideoPacks, Audio Packs). A VOBU starts with exactly one navigation pack andis followed by a number of packs containing presentation data. A VOBUrepresents a presentation time of 0.4 seconds to 1 second. Themultiplexer must calculate and add the dynamic navigation data i.e. itmust create a navigation pack (NV_PCK) as the first sector of each VOBU.The navigation pack contains the Presentation Control Information (PCI)and the Data Search Information (DSI). That is, it contains informationabout search information and how the presentation data should bepresented e.g. highlight information, seamless information, locations.Hence, the DSI and PCI is dispersed throughout the Presentation Data ofthe VOBS. PCI is the navigation data to control the VOBU. DSI is thenavigation data to carry out seamless playback of the VOBU i.e. fastforward, fast backwards, slow motion. There are three forward referencesi.e. a field containing data that requires location information outsidethe VOBU (in the forward direction): DSI/VOBU_SRI (FWDx), DSI/SMLSML_PBI (VOB_V_E_PTM) and DSI/SYNCI (A_PCKA 0). The assigning of valuesto the various fields of the NAV_PCK structures is given below withspecial reference to forward referencing.

In the General Information (PCI_GI) three forward references outside aPES packet exist. They are not forward references within the VOBU.

-   VOBU_S_PTM: Presentation Start Time of the video data in the VOBU.    Since a GOP is VOBU aligned, this address is within the VOBU. If    there is no video data in VOBU then the presentation start of    imaginary video data is described.-   VOBU_F_PTM: Presentation End Time of the video data in the VOBU. By    definition this is an address within a VOBU-   VOBU_SE_E_PTM: Presentation time of sequence_end_code of the video    data in VOBU. By definition this is an address within a VOBU    In addition C_ELTM: a backward reference (requiring cell start    time).

In Angle Information for non seamless (NSML_AGLI) no forward referencesexist. When the angle block does not exist, the related (36) bytes canbe zero. Also in the Highlight Information (HLI) no forward referencesexist. These 22 bytes are set to zero. The logic is: HLI_SS is set to 00since valid HLI is non existence (no sub pictures). If HLI_SS is zerothen the rest of the structure is to be invalid. Further in RecordingInformation (RECI) no forward references exist. The only valid fieldsare ISRC_V and ISRC_A0, because we are dealing with 1 audio stream(stream 0) and 1 video stream. All other fields are zero. The ISRCcontains country code, copyright holder content, recording year andrecording number information. These may be set to zero, or they arecandidates for hard-coded or user defined information. For AngleInformation for seamless (SML_AGLI), since angle blocks do not exist,there are 54 bytes of zero.

In Seamless Playback Information (SML_PBI), when a VOBU is not part ofan ILVU, 2 forward reference exists. One is outside the VOBU i.e. theVOB_V_E_PTM. The remainder of the fields are filled as zero. VOB_V_S_PTMdescribes the presentation time of the first GOP in VOB. Every VOBU ofthe VOB has the same value. So only forward for the first VOBU of theVOB. VOB_V_E_PTM describes the terminating presentation time of the lastvideo frame of the last GOP. The VOB_V_E_PTM for a VOB is fixed for allVOBUs in that VOB. The use of the forward pointer VOB_V_E_PTM isdescribed below.

-   The field is used when a VOB boundary is approached.-   A new VOB is detected by an SCR of zero.-   When PTS=VOB_V_E_PTM of cell N, then PTS becomes VOB_V_S_PTM to play    (seamlessly) cell N+1. That is, there is a discontinuity in the    PTSs.-   The VOB_V_E_PTM is used to inform the hardware clock and all    decoders (audio, video, sub-picture) at what moment, the clock is    reset to the VOB_V_S_PTM of the next VOB. A practical situation is a    sequence of 3 VOBs, in which due to parental control, the second VOB    must be skipped, and the 1st and 3rd must still be played    seamlessly. There is a problem with the PTSes because the end PTS of    VOB−1 can not be the same as the start PTS of VOB−3. As a solution,    each VOB has its own PTS domain, and that starts with zero. Well, in    fact, the SCR of each VOB starts exactly with zero, and the start    PTS is a value slightly higher than zero. Consider the SCR as DTS    time, so that there must be some delay for presentation at time PTS.    In the recording process the VOB_V_E_PTM is calculated to a fixed    value, which may be an arbitrary value, which gives some deviations    in the playing time control system just described. In an embodiment    the playing time of the VOB is set to a fixed value and deviations    are limited by starting a new VOB when the current VOB has the fixed    length. For example the fixed length for the VOB can be one minute,    and the same time can be used for a fixed size Cell length. As the    fixed length is known the correct value for the forward pointer    VOB_V_E_PTM can be inserted, because it can be directly calculated    from said fixed size. Summarizing VOB_V_E_PTM can be solved by:    fixing the size of a VOB (in terms of bytes), or alternatively    filling in a default time, i.e. no fully correct playing time    display for the user.

The VOBU Search Information (VOBU_SRI) is the structure that concernsforward references the most. All fields give information of data outsidethe VOBU. The structure describes the start address of VOBUs presented0.5*n second in the forward and backward direction as shown in FIG. 18.However the pointers do not go outside the cell boundary. If a VOBU doesnot exist then a value of 3F FF FF FF is filled in to indicate that theVOBU does not exist in this place. The VOBU_SRI/FWDx table may be usedfor 3 main purposes in the player: Fast forward, e.g. 2 fast forwardmodes (2 and 8) and/or also 32 speed, Error recovery, e.g. a player mayuse FWD_VIDEO, FWD_3, and FWD_10 when recovering an error in forwarddirection (a degradation may occur when FWD_10 is not filled in), andtime search, which is performed in a repeat mode wherein the playersearches for the VOBU with the indicated time using the forwardreferences. Suppose a cell is 120 seconds and the maximum reference tothe next VOBU is 3 seconds, then finding the required VOBU costs onaverage 20 disc accesses and worst case 39 disc accesses. This costs alot of time for the user, assuming a speed of 4 disc accesses persecond. In an embodiment of a player a better strategy would be to startsearching at the end of a cell, and exploiting the backward referencesthat have been filled in correctly. The usage of FWDI_VIDEO is asfollows: time-search check for next VOBU with video, fast forward checkfor next VOBU with video, check if video is available in some next VOBUof the cell, robustness check if cell has video at all, or errorrecovery: VOBU candidate. The Usage of FWDI_NEXT is testing if VOBU islast in cell The FWDI_VIDEO are determined for nearby VOBUs by referringto the contents of the buffer 30, and are calculated for more distantVOBUs by assuming said VOB size. Summarizing, the Forward References(outside VOBU) in the DSI of the Navigation Pack are FWDIx(DSI/VOBU_SRI) are filled in as follows. Set the fields outside thebuffer size to 3F FF FF FF. Alternatively the fields to outside thebuffer size may be set to the last valid VOBU known. In an embodiment,after the first N FWDI pointers which are correctly filled in based onthe video information in the buffer, the next M FWDI pointers areidentical to the latest correct one. Thereafter the remaining FWDIpointers indicate the end of the Cell. In an embodiment also thebackward pointers in the VOBU search information are adapted similarlyto the calculation of the forward pointers. Now a players will behavesymmetric, i.e. will have the same deviating behavior for in fastforward and fast backward reproduction.

Other alternatives are:

-   Fixing the duration of a VOBU to say 0.5 seconds to ensure that the    FWDIx pointers could be calculated (by extrapolation) during the    first pass of recording.-   Use small cells (fitting in buffer 30). Since these forward    references are not valid outside the cell then using very small    cells, they no longer become problems.

The Synchronous Information (SYNCI) is the address information of theaudio data and sub picture data presented synchronously with the videodata of the VOBU. Since we are not dealing with sub pictures and onlyone audio then A_SYNCA 0 is the only field that must be filled in. Zerois filled in for all other fields. Two pieces of information are neededfor the A_SYNCA 0 field: A_PCK location is set to 0 if after this NV_PCKor 1 if before, and A_PCKA states how many sectors before or after theNAV_PACK its target is. Obviously, A_PCKA is indeed a forward reference.It represents the “skew” between the audio and video. The maximum numberof VOBUs AFTER the video can an audio pack occur is 5, assuming VOBU is0.4 seconds (minimum size). A_PCKA can refer to as far ahead as VOB+3.The maximum delay between Audio and Video is 5. The maximum demultiplexbuffer delay of an audio frame, in bytes, is the audio buffer size. Themaximum buffer delay can be expressed as 4096 bytes, 21.3 frames or0.512 seconds. As the maximum total is 5 VOBUs, the recorder accordingto the invention is preferably equipped with a buffer 30 large enough tocontain at least 5 VOBUs, which enables the forward references to bedetermined from the real-time data within the buffer, which in practicerequires around 3 Mbytes. Further the allowed amount of “skew” betweenan audio or video (currently it is −0.5s to +1s), may be limited to−0.5s to 0.8s, which gives a smaller required buffer. Ultimatelyensuring the size of a VOBU may be sufficient, if amount of allowable“skew” is maximum 1 VOBU. Alternatively a default value may be filledin, indicative that no pointer is available.

Further the functions for creating VOB, CELL AND VOBU are discussedshowing the consequences for the multiplexer. The Multiplexer constructsone VOB per execution. A VOBS consists of one or more VOBs. For thisapplication the VOBs are placed consecutively in a VOBS. A VOB is(approximately) a Program Stream. The differences are, that it is notterminated by an MPEG_program_stream_end_code, but still it has to startwith a zero SCR. The maximum number of VOBs in a VOBS is 65535. Whenmore than one VOB is placed in a VOBS then we must consider “seamlessplay of VOBs”. The DVD Standard states that Video Streams and AudioStreams must be completed within the VOB. The definition of completedis, that the beginning of each stream shall start from the first data ofeach access unit, and the end of each stream shall be aligned in eachaccess unit. This matters because it means that the audio and videodecoding buffer delay is restricted at this point.

When two VOBs, each in one contiguous block, are placed consecutively ina VOBS then an audio gap may occur between the two VOBs if the videostream of the first VOB is longer than it's audio stream. The audio gapis seen as a non seamless feature. To ensure seamless play, in thiscase, the audio gap should be removed so that the audio streams alsojoin i.e. lip synchronization. As an example the audio of VOB1 issomewhat shorter than the video. VOB1 contains a video stream and anaudio stream, VOB2 contains also a video stream and an audio stream, andVOB1 audio is 40 ticks shorter than it's video counterpart. TheMultiplexer deals with such situation as follows. An audio gap wouldexist if we started the audio stream of VOB2 at the same time as thevideo of VOB2, i.e. non-seamless. The removal of the audio gap isobtained by moving the audio stream 40 ticks earlier than the video.This is equivalent to saying that the encoding should have been 40 ticksearlier to ensure lip synchronization. The audio gap is not moved tohide the gap. The gap is there. In an embodiment of the process it ismoved to a more convenient place, e.g. at a scene change. It cannot justbe ignored, as after a number of gaps it would accumulate and eventuallyhave a lip sync problem.

For adding, deleting and moving VOBs, from a presentation data point ofview, the following applies. The process of appending a VOB to the endof a VOB means that the existing VOBs are not affected. The process ofremoving a VOB within a VOBS implies that re-numbering of VOB id afterthe VOB must be performed. The process of inserting a VOB boundarywithin a VOB is not a feasible option. For the Cell Boundary thefollowing applies. A Cell is an integral number of VOBUs. The minimumsize of a cell is 1 VOBU and hence 0.4 seconds. The maximum size of acell is the size of the VOBS i.e. minimal one cell. A Cell is notnecessarily self contained i.e. does not necessarily contains all audioassociated with its video. A cell begins with a GOP i.e. video data, sothe cell must start at a GOP boundary i.e. cell boundaries are at thestart of a GOP. Cells have very little affect on the generation of aProgram Stream. Cell information is found within the Navigation Pack ofa VOBU, as follows:

-   The Cell ID (1 byte) and VOB Id (2 Bytes) uniquely define a cell    within a VOBS. These are found in the DSI_GI of a Navigation Pack.    Therefore the maximum number of Cells per VOB is 255.-   C_ELTM (of PCI_GI and DSI_GI within a Navigation pack): elapsed time    of a cell.    Note that the VOBU Search Information (VOBU_SRI) does not reference    outside the Cell. That is the structure that references VOBUs up to    120 seconds ahead and 120 seconds behind. The Cell ID starts at 1    and must increment by 1 within a VOB i.e. must be consecutive.

Although the invention has been explained by embodiments using theDVD-video format, it may be applied for any format for real-time datarequiring non-causal control data to be written multiplexed within thereal-time data itself. Further, the scope of the invention is notlimited to the embodiments, and the invention lies in each and everynovel feature or combination of features described above. It is noted,that the invention may be implemented by means of hardware and/orsoftware, and that in this document the word ‘comprising’ does notexclude the presence of other elements or steps than those listed andthe word ‘a’ or ‘an’ preceding an element does not exclude the presenceof a plurality of such elements, that any reference signs do not limitthe scope of the claims, that ‘means’ may be represented by a singleitem or a plurality and that several ‘means’ may be represented by thesame item of hardware.

1. A recorder comprising: an input that receives real time information;a write head that writes information encoded as optically readable markson a track of a record carrier; a memory that buffers the real timeinformation from reception and at least until it is written by the writehead on the track of the record carrier; processing means forsubdividing the real time information into units and for determiningplayback parameters to control the playing of the real time informationfrom the record carrier and for adding the playback parameters into theunits, and for controlling the write head for writing the units onto therecord carrier, the playback parameters including jump informationrelated to a distance to jump to other recorded information on therecord carrier when the real time information is played, wherein: insome cases, the jump information is first jump information that isdetermined in a first way from other real time information that iscontained in other units than the jump information; and in other cases,the jump information is second jump information that is determined in asecond way based on a predefined value, the second way being differentthan the first way of determining jump information.
 2. The recorder ofclaim 1 wherein the other real time information is subsequent otherinformation, the subsequent other information being received after thereception of the real time information that is contained in the unitcontaining the jump information, and units containing the subsequentother information being recorded after the recording of the unitcontaining the jump information.
 3. The recorder of claim 1 wherein theother recorded information for which second jump information isdetermined, is always subsequent real time information, the subsequentreal time information being received after the reception of the realtime information that is contained in the unit containing the jumpinformation, and unit containing the subsequent real time informationbeing recorded after the recording of the unit containing the jumpinformation.
 4. The recorder of claim 1 wherein the second jumpinformation includes information indicating a predefined distance thatis significantly shorter than the distance to the other recordedinformation.
 5. The recorder of claim 1 wherein the second jumpinformation includes a predefined value indicating that the jumpinformation does not indicate a distance to the other recordedinformation.
 6. The recorder of claim 1 wherein the second jumpinformation includes a predefined value that only indicates that thedistance to the other recorded information is more than a predefinedamount.
 7. The recorder of claim 1 wherein the second jump informationindicates an estimate of the distance to the other recorded information.8. The recorder of claim 7 wherein the estimate of distance to the otherrecorded information is calculated based on an average distance for areal time period of the jump.
 9. The recorder of claim 1 wherein thefirst jump information includes the position of the other recordedinformation on the record carrier.
 10. The recorder of claim 1 whereinthe first jump information is independent of the predefined value andthe second jump information is independent of the other real timeinformation contained in other units.
 11. The recorder of claim 1wherein the jump information is first jump information when the otherrecorded information is contained in the memory when the jumpinformation is determined and otherwise is second jump information. 12.The recorder of claim 1 wherein the jump information includes theposition of the last unit in the memory when the other recordedinformation is not in the memory when the jump information isdetermined.
 13. The recorder of claim 1 wherein the format of the recordcarrier complies with a DVD-video standard.
 14. A player comprising: aread head for reading units of real time information encoded asoptically readable marks on a track of a record carrier; processingmeans for extracting playback parameters from the units read from therecord carrier and controlling the playing of the real time informationdepending on the playback parameters, the playback parameters includingjump information related to a distance for jumping to other recordedinformation when the real time information is played, the controllingincluding jumping to other recorded information on the record carrierdepending on the jump information; the jumping including: jumping anindicated distance and immediately reading the other recordedinformation when the jump information is an indication of the distanceto the other recorded information; and jumping a predefined distance andthen searching for the other recorded information when the jumpinformation is a predefined value that indicates that the jumpinformation is not the distance to the other recorded information. 15.The player of claim 14 wherein the other recorded information is at apredefined period of the real time subsequent to the real time of theinformation in the unit containing the jump information, and thesearching includes reading one or more units of information after thejump and determining the real time of the information read after thejump.
 16. The player of claim 14 wherein the playback parameters includebackward pointers for searching for the other recorded information. 17.A record carrier comprising: a substrate; a track on the substrate;units of real time information recorded in the track, the units alsocontaining playback parameters to control the playing of the real timeinformation from the record carrier, the playback parameters includingjump information related to a distance for jumping to other recordedinformation on the record carrier when the real time information isplayed, and wherein the jump information includes: first jumpinformation that indicates the distance to the other recordedinformation; and second jump information that does not indicate thedistance to the other recorded information.
 18. The record carrier ofclaim 17 wherein a portion of the other jump information is for a fastplay mode in which the other recorded information is at a predefinedperiod of real time from the information contained in the unitcontaining the other jump information.
 19. The record carrier of claim17 wherein the parameters include backward pointers that are indicationsof distances backward to the other recorded information.
 20. A recordercomprising: an input for receiving units of real time information; awrite head for writing the units of real time information encoded asoptically readable marks on a track of a record carrier; processingmeans for determining playback parameters to control the playing of thereal time information from the record carrier and for adding theplayback parameters into the units, and for controlling the write headfor writing the units of real time information on the record carrier,the playback parameters including jump information related to a distanceto jump to other recorded information on the record carrier when thereal time information is played, the jump information including: firstjump information that is an indication of the distance to the otherrecorded information, the first jump information being determined whendistance to the other recorded information can be determined when thejump information is determined; and second jump information that is notan indication of the distance to the other recorded information, thesecond jump information being determined when the distance to the otherrecorded information can not be determined when the jump information isdetermined.
 21. The recorder of claim 20 wherein the indication ofdistance to the other recorded information is a position of the otherrecorded information on the record carrier.
 22. A recorder comprising:an input for receiving real time information; a write head for writinginformation encoded as optically readable marks on a track of a recordcarrier; a memory for buffering the real time information from receptionuntil it is written; processing means for subdividing the real timeinformation into units and for determining playback parameters tocontrol the playing of the real time information from the record carrierand for adding the playback parameters into the units, and forcontrolling the write head for writing the units onto the recordcarrier, the playback parameters including jump information related to adistance to jump to other recorded information on the record carrierwhen the real time information is played, and the jump informationincludes: first jump information that is an indication of the distanceto the other recorded information, the first jump information beingdetermined when the distance to the other recorded information can bedetermined from the real time information in the memory when the jumpinformation is determined; and second jump information that is not anindication of the distance to the other recorded information, the secondjump information being determined when distance to the other recordedinformation can not be determined from the real time information in thememory when the jump information is determined.
 23. The recorder ofclaim 22 wherein the second jump information includes the position ofthe last unit in the memory when the other recorded information is notin the memory when the jump information is determined.
 24. The recorderof claim 22 wherein the second jump information includes an estimate ofthe position of the other recorded information.
 25. A player comprising:a read head for reading units of real time information encoded asoptically readable marks on a track of a record carrier; processingmeans for extracting playback parameters from the units read from therecord carrier and controlling the playing of the real time informationdepending on the playback parameters, the playback parameters includingjump information related to a distance for jumping to other recordedinformation when the real time information is played, the controllingincluding jumping to other recorded information on the record carrierdepending on the jump information; the jumping including: jumping anindicated distance and immediately reading the other recordedinformation when the jump information is an indication of the distanceto the other recorded information; and jumping an indicated distance andthen searching for the other recorded information when the jumpinformation is not an indication of the distance to the other recordedinformation.